Free elections in Nicaragua?

After four-and-a-half years of rule by fiat, the Sandinistas are trying to institutionalize their revolution by holding elections. But are they serious? Do they really intend to allow reasonably free elections? And will they allow any opposition parties to continue in the long term thereafter?

Well informed diplomats here think that the answer to all three questions is ''yes.''

These sources explain that the country's severe economic problems are forcing the Sandinistas toward compromise. The government badly needs foreign aid to keep going, and it knows it will have to hold an election that seems fair to the international community in order to keep the door open for aid.

''The Sandinistas will continue to be in an economic mess for at least the next five years,'' one diplomat says. ''To survive, they have got to have external financial resources. Because the Soviets are not giving enough, some of this will have to come from the West - from Western Europe, Venezuela, Mexico.

''It is clear to the Sandinistas that much of this aid will be tied into people's political judgment about the direction of the revolution.''

The Sandinistas also hope an election will spur the nation's private sector and middle class to help get the economy moving again, this diplomat says. Gaining the confidence of this group is vital because the private sector controls much of the country's earnings. The government has learned that the middle classes will become productive only if their fear of communism is calmed, he says.

These are the reasons the Sandinistas are likely to allow opposition parties and private enterprise to have a larger political role. But there are also risks in such a compromise for the Sandinistas.

They cannot be sure how many votes their own Sandinista National Liberation Front (FSLN) would win in a free election. The Monitor has learned that the Sandinistas have already tested the electoral waters by commissioning a poll of 4,000 Nicaraguans (a large sampling for this country).

The survey, conducted in November by the Statistic Institute of Spain, showed the Sandinistas would get only 35 percent of the vote if the voting age remained age 18 and the FSLN ran alone. But if the FSLN ran in an alliance with the parties of the Patriotic Front, it would get 45 percent of the vote.

The poll also showed the Sandinistas would substantially increase their standing - and win 55 percent of the vote - if the voting age was lowered to 16 and the FLSN ran with the Patriotic Front. Last month the Sandinistas announced they would introduce a bill to lower the voting age, a move that attracted a great deal of opposition criticism.

Most observers believe, however, that the Sandinistas will win the election. But there is disagreement among the Sandinistas themselves over the advisability of holding elections. This split within the leadership may be the reason for new reports that the Sandinistas will start with legislative elections on Nov. 4 - postponing presidential elections until after a constitution is approved.

The presidential election plan was pushed by junta coordinator Daniel Ortega Saavedra and his brother, Defense Minister Humberto Ortega Saavedra, in alliance with directorate members Jaime Wheelock Roman and Carlos Nunez sources say. The plan was apparently opposed by radical directorate members Tomas Borge Martinez, minister of the interior, and Bayardo Arce.

The consensus among Western diplomats here is that the Sandinistas will not, as some fear, renege on their agreement and crack down on the opposition soon after the elections.

''They know,'' one diplomat said, ''that backsliding would only make them look far worse than they do now in the eyes of the international community.

Opposition parties must now decide whether they will participate in these elections. It is a difficult choice. They do not trust the Sandinistas, they fear unfair elections, and they worry about the possibility of a post-electoral crackdown.

They are also concerned that their participation in elections would imply consent to the institutionalization of Sandinista hegemony. If the opposition parties do not participate, there is the possibility that Nicaragua's leaders will become more radical.

Most observers believe that the Sandinistas will not play dirty with the electoral process itself, but in the words of another Western diplomat, ''They are setting the rules of the game, and the rules will not operate to their disadvantage.''

The opposition parties, weak to begin with, have been further weakened by several years of repression. Observers wonder how much strength they can gain in only a few months of policital liberalization in a society throroughly controlled by the Sandinistas? The army, the government appartus, mass organizations, and key sections of the economy are all in FSLN hands.

Observers here expect the opposition parties to demand two concessions from the Sandinistas as a price for their electoral participation: lifting press censorship (already somewhat relaxed) and access to TV.

Even with more media freedom and the return of additional anti-Sandinista exile leaders (such as Alfonso Robelo), the Sandinistas are still expected to win.